This invention relates to systems for receiving and evaluating empty beverage containers of a type known in the trade as returnable. These are containers, usually glass bottles, for which the beverage purchaser is charged a deposit fee at the time of purchase. When the purchaser returns the empty container to a designated redemption center, the deposit fee is refunded. Most beverage sales outlets also operate redemption centers, and the operation of these centers is usually a troublesome matter which takes clerks away from other more profitable tasks.
Beverages are commonly sold in containers of many different sizes, and in cartons containing groups of six or eight such containers. The customer may return the containers either individually or in cartons and may mix different types of containers in a single carton. It is the task of the redemption center clerk to sort or classify the containers in accordance with their deposit values and to calculate the refund which is due. The clerk may make an actual refund or may give the customer a refund slip which can be redeemed at another location. This operation is so unprofitable that many supermarkets simply operate on an honor system, whereby customers stack their empties at a receiving location and report the return to a checkout clerk, who makes the appropriate refund.
An alternative to the above described redemption techniques is an automatic system such as a system of the type described in Planke U.S. Pat. No. 3,955,179. This system has a pair of conveyors, one for individual empty bottles and one for cartons. In operation the customer places the returned bottles and cartons on the appropriate conveyor for transportation through an illumination station. At the illumination station the containers are illuminated by a beam of collimated light, and a shadow of the containers is projected against an array of photodetectors. The containers are identified by their shadows. This identification results in control signals for a logic network which computes the amount of the refund and controls the printing of a refund slip by an associated printer.